The principal objective of this project is to assess the quality of care provided to patients with or at-risk for human immunodeficiency virus (HIV) infection by primary care physicians with varying degrees of experience and training related to HIV. New methods will be developed for use in conjunction with established strategies to assess the competence of primary care physicians in identifying, managing, and counseling patients with or at-risk for HIV infection. A standardized patient examination will be developed to evaluate the knowledge and interviewing, physical examination, and counseling skills of physician-subjects. Modified versions of existing health status measures will be used to obtain information directly from patients followed by the physician-subjects concerning physicians' effectiveness in screening for risk factors for HIV infection and patient outcomes including patients' compliance with prevention and therapeutic regimens, satisfaction with care, and functioning. Information about patient outcomes will also be obtained from patients with cancer to determine similarities and differences between care provided to HIV-infected patients compared to patients with another chronic or terminal disease. Three groups of primary care physicians will be recruited as subjects: 1) one group with no personal experience with patients with HIV infection; 2) one group with minimal experience with HIV-infected patients; and 3) one group with moderate to extensive experience with HIV-infected patients. Extensive background information concerning the physician-subjects' practice patterns, training backgrounds, demographic characteristics and attitudes towards patients with different risk factors for HIV infection will be obtained. Patient-related characteristics that may affect care will be identified, including patient preferences regarding therapy, associated illnesses, socioeconomic status, and source of payment. The effects of physicians' experience with HIV infected patients on their performance in identifying, managing, and counseling patients with or at-risk for HIV infection will be determined using univariate methods. Multivariate analyses will be used to determine the effects of other physician-related and patient-related variables on care of HIV-infected patients. The methods used in this project will permit an in-depth study of the interaction between patients with or at-risk for HIV infection and primary care physicians, and will provide new information to determine the effects of this interaction on patient outcomes.